Frost history / Duncan, OK
Duncan, OK: frost dates by year
Last spring and first fall frost at NOAA station USC00342660, 1951 to 2011, measured from daily minimum temperatures.
Elevation 1,125 ft, 34.501, -97.959. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Mar 25 | Nov 9 |
| Earliest | Feb 28 (1961) | Oct 7 (1952) |
| Latest | Apr 19 (1953) | Dec 8 (1998) |
| Trend | 1.3 days earlier per decade | 1.2 days later per decade |
| Years with data | 48 | 51 |
At 28°F (hard freeze) the median last spring date is Mar 15 and the median first fall date is Nov 19.
The trend is a straight-line fit through the years with a freeze. A positive spring trend means the last frost now comes later. Short or patchy records give noisy trends.
Chart
Last spring frost (32°F)
First fall frost (32°F)
Dots are single years. The gray line is the median, the green line the fitted trend.
Year by year
| Year | Last spring 32°F | First fall 32°F | Last spring 28°F | First fall 28°F |
|---|---|---|---|---|
| 2011 | Mar 15 | Nov 4 | Feb 12 | Nov 28 |
| 2010 | Mar 23 | Nov 18 | Mar 23 | Nov 26 |
| 2009 | Apr 7 | Nov 18 | Mar 29 | Dec 3 |
| 2008 | no data | Nov 15 | no data | Nov 21 |
| 2007 | Apr 7 | Nov 15 | Mar 4 | Nov 22 |
| 2006 | Mar 25 | Nov 2 | Mar 24 | Nov 18 |
| 2005 | Mar 17 | Oct 24 | Feb 10 | Nov 16 |
| 2004 | Feb 28 | Nov 25 | Feb 27 | Dec 1 |
| 2003 | no data | Nov 24 | no data | Nov 24 |
| 2001 | Mar 20 | Nov 20 | Mar 1 | Nov 20 |
| 2000 | Mar 12 | Oct 9 | Feb 14 | Nov 13 |
| 1999 | Mar 16 | Nov 3 | Mar 15 | Dec 6 |
| 1998 | Mar 22 | Dec 8 | Mar 13 | Dec 21 |
| 1997 | Apr 14 | Oct 27 | Apr 13 | Nov 15 |
| 1996 | Mar 28 | Nov 17 | Mar 28 | Nov 24 |
| 1995 | Apr 12 | Nov 4 | Mar 9 | Nov 11 |
| 1994 | Apr 7 | Nov 28 | Mar 10 | Nov 28 |
| 1993 | Mar 17 | Oct 30 | Mar 15 | Oct 30 |
| 1992 | Mar 23 | Nov 5 | Mar 11 | Nov 5 |
| 1991 | Mar 16 | Nov 1 | Feb 27 | Nov 1 |
| 1990 | no data | Oct 22 | no data | Nov 28 |
| 1989 | Apr 11 | Oct 19 | Mar 22 | Oct 19 |
| 1988 | Mar 19 | Nov 16 | Mar 19 | Nov 28 |
| 1984 | Mar 20 | no data | Mar 9 | no data |
| 1983 | Apr 15 | Nov 11 | Mar 11 | Nov 25 |
| 1982 | Mar 7 | Nov 13 | Mar 7 | Nov 13 |
| 1981 | Mar 19 | Nov 10 | Feb 14 | Dec 17 |
| 1980 | Mar 18 | Oct 29 | Mar 6 | Nov 19 |
| 1979 | Mar 6 | Nov 10 | Mar 5 | Nov 23 |
| 1978 | no data | Nov 17 | no data | Dec 4 |
| 1977 | no data | Nov 10 | no data | Nov 10 |
| 1975 | Apr 3 | no data | Apr 3 | no data |
| 1974 | Apr 5 | Nov 15 | Mar 24 | Nov 30 |
| 1973 | no data | Nov 21 | no data | Dec 5 |
| 1972 | Mar 31 | Nov 16 | Mar 2 | Nov 23 |
| 1971 | Apr 7 | Nov 7 | Apr 7 | Nov 19 |
| 1970 | Apr 5 | Nov 3 | Apr 2 | Nov 15 |
| 1969 | Mar 26 | Nov 4 | Mar 13 | Nov 15 |
| 1968 | Apr 5 | Nov 9 | Mar 23 | Nov 9 |
| 1966 | Mar 29 | Nov 2 | Mar 24 | Nov 2 |
| 1965 | no data | Nov 29 | no data | Dec 16 |
| 1964 | Mar 29 | no data | Mar 21 | no data |
| 1963 | Mar 7 | Nov 2 | Mar 7 | Dec 9 |
| 1962 | Mar 15 | no data | Mar 15 | no data |
| 1961 | Feb 28 | Nov 3 | Feb 28 | Nov 29 |
| 1960 | Mar 18 | Nov 10 | Mar 18 | Nov 10 |
| 1959 | Mar 7 | Nov 5 | Mar 6 | Nov 6 |
| 1958 | Mar 20 | Nov 18 | Mar 15 | Nov 18 |
| 1957 | Apr 14 | Oct 26 | Apr 13 | Oct 26 |
| 1956 | Apr 11 | Nov 9 | Mar 16 | Nov 9 |
| 1955 | Mar 28 | Nov 3 | Mar 28 | Nov 3 |
| 1954 | Apr 1 | Oct 30 | Mar 14 | Dec 13 |
| 1953 | Apr 19 | Nov 9 | Mar 4 | Nov 9 |
| 1952 | Apr 10 | Oct 7 | Mar 24 | Nov 11 |
| 1951 | Apr 12 | Nov 2 | Mar 19 | Nov 2 |
"none" means the station recorded no freeze at that threshold in that half of the year. "no data" means more than 10% of the season's daily readings were missing. Years with no usable data are left out. See the methodology for the rules, and the ZIP lookup for 1991 to 2020 frost probabilities.